Study on flow characteristics of the cryogenic throttle valve for superfluid helium system

As one of the important methods to obtain superfluid helium, throttling has been widely used due to its simple equipment. The cryogenic throttle valve, serving as a vital component in the throttling process, directly impacts the performance of the superfluid helium system. In this study, velocity and pressure field inside valve is numerically simulated by using computational fluid dynamics (CFD), and the flow characteristics of the valve are analyzed by theoretical calculations and experiments. Moreover, influences of cone angle, unilateral minimum clearance, structure type and working medium type on flow field distribution and flow characteristics of valve are studied by altering structural parameters of spool and working medium. The results demonstrate that increasing cone angle and unilateral minimum clearance can enhance flow capacity of valves, but influence of cone angle is more obvious. Changing the spool type will significantly alter the flow characteristics of the valve, while changing the working fluid type will only affect the velocity and pressure inside the valve.